• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 3
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 21
  • 8
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aspects of the biology of the musselcracker, Sparodon Durbanensis, and the bronze bream, Pachymetopon grande, (Pisces : Sparidae), with notes on the Eastern Cape recreational rock-angling and spear fisheries

Clarke, John Ross January 1988 (has links)
The musselcracker, Soarodon durbanensis, and the bronze bream, Pachymetopon arande, are important components of rock-angling and spearfishing catches In the Eastern Cape. Aspects of their biology, including age and growth, reproduction, nursery areas and feeding, were Investigated to provide a basis for the rational exploitation of the resource. Both species are slow-growing and long-lived. Growth in S. durbanensls was described by the von Bertalanffy growth equation: Lt(mm) = 1021.2(1-e⁻°.°⁹°°⁽t ⁻° .⁷°⁹⁾). The von Bertalanffy growth model did not describe the total data set in P. grande, but by excluding the zero and one year old fish the data were described by: Lt(mm) = 461.1(1-e⁻°.¹⁵³⁽t ⁺¹.⁶⁴°⁾). Detailed histological examination of gonadal development showed that S. durbanensis and P. grande are rudimentary hermaphrodites. Both species had restricted breeding seasons which coincided with peak exploitation. Results indicated that both species are group spawners with pelagic eggs. Size at 50% maturity in S. durbanensis and P. grande was determined at 350 and 300mm fork length, respectively, corresponding to ages of 4.5 and 5.5 years. Intertidal pools functioned as nursery areas for S. durbanensis during the first year, whereas subtidal waters were more important for larger juveniles. P. grande juveniles were commonly observed on subtidal weed beds to a depth of 10m. A size-related change in the diet of S. durbanensis was observed. The juveniles were omnivorous, feeding predominantly on gastropods, echinoids and chlorophytes. The adults fed on a variety of large, reef-associated invertebrates. P. grande were omnivorous, with macroalgae being the principal dietary component. This species appears to utilise the storage and extracellular carbohydrates of the macroalgae. Results showed that macroalgal degradation by gut endosymbionts and the utilisation of macroalgal epibionts does not appear to occur in this species. A detailed analysis of catch composition and catch per unit of effort In the Port Elizabeth rock-angling fishery and the Eastern Cape spearfishery emphasised the recreational importance of S. durbanensis and P. grande. The localised distribution, slow growth and late maturation in both species results in their being susceptible to over-exploitation in these size-selective fisheries. Current legislation protecting these fish is discussed in relation to the findings of this study and additional management measures are proposed.
2

Organic iron requirements of gilthead sea bream (Sparus aurata)

Samartzis, Alexandros January 2014 (has links)
The aim of the current study was to determine the organic iron (Fe) requirements of gilthead sea bream (Sparus aurata). A total number of four experiments have been carried out each one for 12 weeks, in order to address and extend the knowledge on nutritional issues and challenges related with the culture of the gilthead sea bream in the Greek aquaculture industry and therefore enhance the fish health status under intensive culture conditions. These experiments aimed to determine the optimum level of organic Fe supplemented in commercial type diets of sea bream, the comparison between an organic Fe form and two inorganic Fe forms added in the diet of the fish, the effect of supplemented organic Fe on sea bream species exposed to oxygen deprivation stressors related to poor aquaculture husbandry practices and finally the interaction of organic Fe in the diet of sea bream with various levels of other trace minerals (Zn, Cu). The parameters evaluated were the growth performance of the fish, the Fe concentration in three selected tissues (the spleen, the liver and the muscle), the haematological status of the fish (the haematocrit, the red blood cell count, and the haemoglobin) and both the humoral and cellular immunology of the fish (the antibacterial activity of serum and the respiratory burst respectively). 150 mg/Kg of added organic Fe appears to be the recommended level as well as the minimum amount on fish exposed to overstocking conditions. The comparison between the two inorganic Fe forms (Ferrous Sulphate and Ferrous Carbonate) added in the diets show no significant effect on the fish. While, the fish fed the diets with 150 mg/Kg organic Fe and Cu levels lower that 5 mg/Kg had higher Hb values.
3

Biology of two species of sparid on the west coast of Australia

ahesp@murdoch.edu.au, Sybrand Alexander Hesp January 2003 (has links)
Various aspects of the biology of the tarwhine Rhabdosargus sarba and western yellowfin bream Acanthopagrus latus were studied. The studies on R. sarba have focused on populations in temperate coastal marine waters at ca 32oS and the lower reaches of an estuary (Swan River Estuary) located at the same latitude and in a subtropical embayment (Shark Bay) at ca 26oS, while those on A. latus were conducted on the population in the latter embayment. A combination of a macroscopic and histological examination of the gonads demonstrated that R. sarba is typically a rudimentary hermaphrodite in Western Australian waters, i.e. the juveniles develop into either a male or female in which the ovarian and testicular zones of the gonads, respectively, are macroscopically undetectable. This contrasts with the situation in the waters off Hong Kong and South Africa, in which R. sarba is reported to be a protandrous hermaphrodite. However, it is possible that a few of the fish that are above the size at first maturity and possess, during the spawning period, ovotestes with relatively substantial amounts of both mature testicular and immature ovarian tissue, could function as males early in adult life and then change to females. Although R. sarba spawns at some time between late winter and late spring in Western Australia, spawning peaks later in the Swan River Estuary than in coastal, marine waters at the same latitude and Shark Bay, in which salinities are always close to or above that of full strength sea water, i.e. 35 ñ . While the males and females attain sexual maturity at very similar lengths in the Swan River Estuary and Shark Bay, i.e. L50s all between 170 and 177 mm, they typically reach maturity at an earlier age in the former environment, i.e. 2 vs 3 years old. Thus, length and consequently growth rate influence the timing of maturity rather than age. During the spawning period, only 9 % of the fish caught between 180 and 260 mm in nearshore, shallow marine waters had become mature, whereas 91 % of those in this length range over reefs were mature, indicating that R. sarba tends to move offshore only when it has become gphysiologically ready to mature. The L50s at first maturity indicate that the current minimum legal length in Western Australia (230 mm) is appropriate for managing this species. Oocyte diameter frequency distributions, stages in oocyte development, duration of oocyte hydration and time of formation of post-ovulatory follicles in mature ovaries of Rhabdosargus sarba in the lower Swan River Estuary (32o 03fS, 115o 44fE) were used, in conjunction with data on tidal cycles, to elucidate specific aspects of the reproductive biology of this sparid in an estuarine environment. The results demonstrated the following. (i) Rhabdosargus sarba has indeterminate fecundity sensu Hunter et al. (1985). (ii) Oocyte hydration commences at about dusk (18:30 h) and is completed by ca 01:30-04:30 h, at which time ovulation, as revealed by the presence of hydrated oocytes in the ovarian duct and appearance of newlyformed post-ovulatory follicles, commences. (iii) The prevalence of spawning was positively correlated with tidal strength and was greatest on days when the tide changed from flood to ebb at ca 06:00 h, i.e. approximately when spawning ceases. Spawning just prior to strong ebb tides would lead to the transport of eggs out of the estuary and thus into salinities that remain at ca 35 ñ . The likelihood of eggs being transported downstream is further enhanced by R. sarba spawning in deeper waters in the estuary, where the flow is greatest. (iv) Although mature ovaries were found in R. sarba in the estuary between early July and December, the prevalence of atretic oocytes was high until September, when salinities started rising markedly from their winter minima. Batch fecundities ranged from 2,416 for a 188 mm fish to 53,707 for a 266 mm fish. The average daily prevalence of spawning amongst mature females during the spawning period of R. sarba caught in the lower estuary, i.e. July to end of October, was 36.5 %. Thus, individual female R. sarba spawned, on average, at intervals of ca 2.7 days in each spawning season. Female R. sarba with total lengths of 200, 250 and 300 mm were estimated to have a batch fecundity of 7,400, 20,100 and 54,800 eggs, respectively and annual fecundities of 332,000, 903,000 and 2,461,000 eggs, respectively. Rhabdosargus sarba is shown to undergo size-related movements in each of the three very different environments in which it was studied. In temperate coastal waters, R. sarba settles in unvegetated nearshore areas and then moves progressively firstly to nearby seagrass beds and then to exposed unvegetated nearshore areas and finally to areas around reefs where spawning occurs. Although R. sarba spawns in the lower Swan River Estuary, relatively few of its early 0+ recruits remain in the estuary and substantial numbers of this species do not start reappearing in the estuary until they are ca 140 mm. In Shark Bay, R. sarba uses nearshore mangroves as a nursery area and later moves into areas around reefs. The maximum ages recorded for R. sarba in coastal marine waters (11 years) and Shark Bay (13 years) were far greater than in the lower Swan River Estuary (6 years). However, the maximum lengths recorded in these three environments were all ca 350 mm. Due to the production by size-related movements of differences amongst the lengths of R. sarba at given ages in different habitats in coastal marine waters, the composite suite of lengths at age was not fully representative of the population of this species as a whole in this environment. A von Bertalanffy growth curve, which was adjusted to take into account size related changes in habitat type, significantly improved the fit to the lengths at age of individuals in the composite samples for the population beyond that provided by the unadjusted von Bertalanffy growth curve. This resulted in the maximum difference between the estimates of length at age from the two growth curves, relative to the L‡ derived from the unadjusted von Bertalanffy curve, reaching a value equivalent to 8 %. However, the maximum differences for the corresponding curves for populations in the lower Swan River Estuary and Shark Bay were far less, i.e. 1.7 and 3.2 %, respectively, and thus not considered biologically significant. Rhabdosargus sarba grew slightly faster in the lower Swan River Estuary than in either coastal marine waters or Shark Bay, possibly reflecting the greater productivity of estuarine environments. Acanthopagrus latus is a protandrous hermaphrodite. Detailed macroscopic and histological examination of the gonads of a wide size range of fish, together with a quantification of how the prevalences of the different categories of gonad change with size and age and during the year, were used to elucidate the sequence of changes that occur in the ovotestes of A. latus during life. The scheme proposed in the present study for the protandrous changes in A. latus differed from those proposed for this species elsewhere, but was similar to that of Pollock (1985) for the congeneric Acanthopagrus australis. The ovotestes of functional males develop from gonads which, as in older juveniles, contain substantial amounts of testicular and ovarian tissue. Such ovotestes, and particularly their testicular component, regress markedly after spawning and then, during the next spawning season, either again become ovotestes in which the testicular zone predominates and contains spermatids and spermatozoa (functional males), or become ovotestes in which the ovarian zone predominates and contains vitellogenic oocytes (functional females). Once a fish has become a functional female, it remains a female throughout the rest of its life. The trends exhibited during the year by reproductive variables demonstrate that A. latus in Shark Bay typically spawns on a very limited number of occasions during a short period in August and September and has determinate fecundity. The potential annual fecundities of 24 A. latus ranged from 764,000 in a 600 g fish to 7,910,000 in a 2,050 g fish and produced a mean }1SE of 1,935,000 } 281,000. The total length at which 50 % of A. latus become identifiable as males (245 mm) is very similar to the current minimum legal length (MLL) of 250 mm, which corresponds to an age of 2.5 years less than the age at which 50 % of males become females. Current spawning potential ratios calculated over a range of alternative values for natural mortality (M) for A. latus in Shark Bay suggests that the present fishing pressure is sustainable, but that the current MLL should be reviewed if recreational fishing pressure continues to increase. The age composition and von Bertalanffy growth parameters for Acanthopagrus latus have been determined. The relevant parameters were inserted into the empirical equations of Pauly (1980) and Ralston (1987) for estimating natural mortality (M). Total mortality (Z) was calculated using Hoenigfs (1983) equations, relative abundance analysis and a simulation based on maximum age and sample size.The two point estimates for M for A. latus, which were both 0.70 year-1, greatly exceeded all estimates for Z (range 0.18 to 0.30 year-1), which is clearly an erroneous result. To resolve this problem of inconsistent estimates, a Bayesian approach was developed, which, through combining the likelihood distributions of the various mortality estimates, produced integrated estimates for M and Z that are more consistent and precise than those produced for these two variables using the above methods individually. This approach now yielded lower values for M than Z and a measure of fishing mortality that appears to be consistent with the current status of the fishery. This approach is equally applicable to other fish species.
4

Selection for faster growing black bream Acanthopagrus butcheri

R.Doupe@murdoch.edu.au, Robert Gerard Doupe January 2004 (has links)
In Australia, the widespread clearing of native vegetation has resulted in large areas of once-productive agricultural land being affected by rising saline groundwaters. There is considerable interest among farmers and rural landowners throughout Western Australia, in the possibilities that inland saline aquaculture may offer for a potentially productive use of land and water resources that can no longer support traditional agriculture. Black bream (Acanthopagrus butcheri) appear to be an ideal candidate for the developing saline aquaculture industry of inland Western Australia, however their current maximum growth rates are too slow for profitable production. The high productivity of modern breeds of terrestrial livestock species is primarily due to genetic improvement programs utilising selective breeding, and similar gains have also been made where they have been implemented for aquatic species. Before the growth rate of black bream can be genetically improved, however, it is necessary to estimate both the extent of genetic improvement required and the extent of genetic (co)variation in those growth traits which will be subject to, or affected by, selection. The aims of this study were to: (1) Determine the extent of genetic improvement in growth rate required for black bream to be considered as a profitable aquaculture species. (2) Estimate the potential for growth rate to be improved through heterosis when different black bream strains are crossbred. (3) Estimate the additive genetic variation for growth rate, which exists within populations of black bream. (4) Estimate the genetic (co)variation which exists between growth rate and other production traits. A partial budget analysis investigated whether enhanced growth rates of black bream would improve profitability and justify a genetic improvement program. It was conducted for two different fish production systems; a commercial operation that incurred more operating expenses due to costs associated with farm initiation (stand-alone farm model) and an existing farm that diversified into aquaculture using the saline water resources of established farm dams (integrated farm model). Sensitivity analyses indicated that a 33% increase in growth rate to at least 200g/annum would allow either production system to return a profit at a farm-gate price of AUS$6/kg whole fish, with fish survival rates of 98% for the stand-alone farm and 65% for the integrated farm model. These results provided a breeding objective, being an improvement in growth rate by at least 33%. A complete diallel cross of two black bream populations was used to estimate the comparative advantages that might be gained from straight-breeding and crossbreeding. At 90 days of age, the growth traits of standard length, total length and wet weight, varied significantly among all straight-bred and crossbred lines, and among half-sib groups within lines. Differences among half-sib groups explained 6.8% of the total variance in standard length, 8.3% in total length and 7.1% in wet weight, giving estimated heritabilities over all lines of 0.27 ± 0.11 for standard length, 0.33 ± 0.13 for total length and 0.28 ± 0.12 for wet weight. There was no evidence for heterosis in any traits when straight-bred and crossbred lines were compared, and phenotypic (rP = 0.95 – 0.98) and genetic (rG = 0.63 – 0.69) correlations were high among all growth traits. I used the estimated heritability for wet weight of 0.28 to optimise a factorial mating design from a single population, and to estimate the contribution of additive genetic, nonadditive genetic and maternal effects to variation in growth traits of black bream at 75, 130 and 180 days of age in the hatchery. Maternal genetic and environmental effects were greatest at 75 days of age, accounting for 9.1% of total phenotypic variance in wet weight, 11.4% of variance in standard length and 8.8% of variance in total length. At later ages maternal effects were much reduced, explaining 0.8 – 3.7% of phenotypic variance in growth traits. Additive genetic effects were greatest at 130 days of age, when they accounted for 17.4% of total phenotypic variance in wet weight, 21.4% of variance in standard length and 18.7% of variance in total length. Additive genetic effects were negligible (<1%) at 75 days of age and 4.8 – 5.5% of total phenotypic variance in growth traits at 180 days of age. Non-additive genetic effects (which also included common environmental effects due to families being raised in the same tank) explained 5.8 – 7.3% of total phenotypic variance in growth traits at 75 days of age, but were much smaller at later ages. Variable stocking densities among tanks up to 75 days significantly affected all growth trait measurements below 180 days of age. One of the most important of these traits is feed conversion efficiency. Feed conversion efficiency (FCE) is the effectiveness with which feed is converted to saleable fish product. Feed costs are a major input to aquaculture production systems and genetic changes in FCE may therefore have an important influence on profitability. FCE is usually expressed by a composite measure that combines feed intake and growth rate. The two most common measures are feed conversion ratio (feed intake/weight gain over a specified time interval) and its inverse, feed efficiency. Feed conversion ratio and feed efficiency are measures of gross FCE, because they do not distinguish between the separate energy requirements of growth and maintenance. There is abundant evidence of substantial genetic variation in FCE and its component traits in terrestrial livestock species and, although data are few, the same is likely for cultured fish species. The major problems with selecting from this variation to genetically improve FCE in fish species are: • It appears impractical to measure feed intake on individual fish, so that family mean data must be used. • We do not know the optimal time period over which to test fish for FCE. • We do not know the genetic correlations between FCE under apparent satiation or restricted intake conditions, or between FCE at different times in the production cycle. I measured the relationships between feed intake to apparent satiety and weight gain in replicate half-sib families of black bream at four times over a 56-day test period. After 42 days, I found significant additive genetic variance in both weight gain and feed intake, and a stabilisation in family group variation in both traits. This indicates that 42 days is the minimum test period over which to measure genetic variation for FCE in black bream. There were high, positive phenotypic (and probably genetic) correlations between weight gain and feed intake after 42 days. There was no detectable genetic variation for either feed efficiency (weight gain/feed intake), or residual feed intake, which is the difference between the actual feed intake of an individual and the intake predicted from its body weight and growth rate. I argue that selection for improved FCE might be better achieved not by using a composite measure, but by using a weighted selection index that accounts for the genetic covariance among weight gain, feed intake and other correlated traits.
5

Biodiversity in Swedish Cyprinid Fish: Insights Into Processes of Divergence

Demandt, Marnie H January 2009 (has links)
Uncovering and understanding the processes that have led to the biological diversity we observe today are of fundamental interest in biology. Since direct observation of speciation is usually impossible, knowledge about the processes behind species formation can be gathered by studying mutations, natural/sexual selection, and genetic drift. In this thesis I aim to identify evolutionary processes that cause species divergence and, ultimately, speciation using Swedish cyprinid fish as a model system. Assuming that the demographic history of a population is mirrored in the genome, I studied the effects of a bottleneck on genetic variability in populations of roach. As expected, I found that a decrease in population size caused a decrease in genetic variability, a pattern that was obtained from both microsatellite and mitochondrial data. The importance of hybridization for speciation is debated, however, by analyzing morphology and microsatellites I could show that common bream and white bream and their interspecific hybrids are phenotypically and genetically differentiated and that ongoing geneflow is mainly unidirectional. Ongoing geneflow antagonizes the effect of genetic drift, but by studying isolated populations (= no gene flow) the impact of genetic drift can be assessed. Long-term isolated populations of roach and perch surprisingly showed stable levels of genetic diversity over time despite decreasing effective population size. However, each population genetically diverged during the period of investigation, a finding that is consistent with the effect of drift. An analysis of the systematic relationship of the 18 species of Swedish cyprinids revealed low congruence of phylogenies based on two different genetic markers. The position of the tench remains unresolved and the relationship of common bream and white bream as sister species cannot be confirmed. Within cyprinid fishes, diversification rates reveal a slowdown with time, a pattern that I found also in other fish clades and that is consistent with density-dependent cladogenesis. Overall, based on the findings presented in this thesis I emphasize that the maintenance of genetic variation in populations is essential since genetic variation is the key element for processes of divergence to act upon.
6

O violão na era do disco: interpretação e desleitura na arte de Julian Bream / The guitar in the age of recording: performance and misreading in the art of Julian Bream

Molina Júnior, Sidney José 13 March 2006 (has links)
Made available in DSpace on 2016-04-26T18:15:19Z (GMT). No. of bitstreams: 1 O Violao na Era do Disco.pdf: 1552859 bytes, checksum: 0a6e9bc8f1e3dda79176cc3c97f8225c (MD5) Previous issue date: 2006-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This thesis shows how the classical guitar canon is a phenomenon of the twentieth century in contrast, for example, with the piano, violin and orchestral repertoires, whose canons had been formed step by step since the end of the eighteenth century and dependent as such on the criteria fixed by its interpreters through the medium of sound recording. The project highlights especially, the Age of LPs (1950-90) as the central part of a process where the act of listening to recordings seems to be as important as the edition of music scores. So, for the guitar, the writing is also a sound, and the music is primarily the musicians. Therefore, there are important analogies between the ascension and stabilization of the instrument in the international concert scene and the conceptual development of the recordings, which moves from the Recital LP , simulacrum of live performance, to the Art Work LP , influenced by the historically informed performance and constituting a kind of sound simulacrum of the edited music score. Two important artists who contributed to this process are studied here: Andrés Segovia (1893-1987) and mainly Julian Bream (1933), whose wide phonographic work, released during the second half of the twentieth century, has been analyzed in contrast with the recordings made by Segovia in the first half of the century. Taking that into consideration, authors such as Dahlhaus, Adorno, Lotman, Said and especially Bloom provide decisive conceptual tools for the thesis. Based on this theoretical approach, our study of Juliam Bream s discography has been divided into three moments: the poetical origins (the swerving from Segovia); the middle period (constitution of an independent voice); and the late phase ( misreading of the precursor). The thesis also includes a detailed research of the recordings made by both interpreters and it restores the original context of their albums / Esta tese procura mostrar como ao contrário, por exemplo, dos repertórios pianístico, violinístico e orquestral, cujos cânones formaram-se pouco a pouco desde finais do século XVIII o cânone do violão clássico é um fenômeno do século XX e, como tal, bastante dependente de critérios sonoros fixados por seus intérpretes através de gravações. Em especial, o trabalho destaca a Era dos LPs (aproximadamente 1950-90) como centro de um processo no qual a escuta de discos parece ser ao menos tão importante quanto a edição de partituras. Assim, para o violão, a escrita é também som, e as músicas são antes de tudo os músicos. Há, portanto, fortes analogias entre o processo de ascensão e estabilização do instrumento no cenário internacional de concertos e o desenvolvimento conceitual do disco, que caminha do LP Recital , simulacro da performance ao vivo, para o LP Obra , influenciado pela performance historicamente informada e espécie de simulacro sonoro da partitura editada. Dois artistas centrais para esse processo são estudados no trabalho: o espanhol Andrés Segovia (1893-1987) e sobretudo o inglês Julian Bream (1933), cuja larga obra fonográfica lançada durante a segunda metade do século XX analisamos contra o pano de fundo das gravações realizadas por Segovia na primeira metade do século. Para tanto, autores como Dahlhaus, Adorno, Lotman, Said e especialmente Bloom fornecem ferramentas conceituais decisivas para a fundamentação teórica da pesquisa. A partir desses pressupostos, dividimos nosso estudo crítico da discografia de Julian Bream em três momentos: as origens poéticas, onde predomina o desvio em relação a Segovia; o período médio, caracterizado pela constituição de uma voz própria independente; e a fase de maturidade, onde ocorre a desleitura do precursor. Nesse percurso, o trabalho realiza também um minucioso levantamento das gravações dos dois intérpretes e recupera o contexto original de seus discos
7

Life Cycle Assessment of Minced Bream : A case study performed in collaboration with Axfoundation / Livscykelanalys av braxenfärs : En fallstudie genomförd i samarbete med Axfoundation

Andersson, Katja January 2021 (has links)
The need for more sustainable protein sources is growing globally due to the significant climate impact from the food system and the estimated population growth. Although vegetarian protein sources have been proven to be sustainable alternatives, there may exist additional resources that currently are not utilized but potentially could contribute as sustainable protein sources. Life Cycle Assessment (LCA) is an internationally standardized tool used to assess the potential environmental impacts of a product or service throughout its entire life cycle. The results from a recently conducted LCA for Swedish carp species showed that the average potential climate impact was 0.77 kg CO2-eq per kg of edible product, which is significantly lower than more commonly consumed protein sources. The bream is a carp fish that previously was consumed in Sweden, but now is caught only as a by-catch that is released back.  This study aims to assess the potential environmental impacts of minced bream produced in Stockholm and utilizing bream caught as by-catch to wild capture fishery in Mälaren. The study also investigates how the potential environmental impacts may change in alternative systems and how the potential climate impact compares to the potential climate impact of other protein sources consumed in Sweden. The results of the study confirm many of the conclusions made in reviewed literature, such as the wild capture fishery and transports being identified hotspots. The results also show a low potential environmental impact of the minced bream in the current system but significant increases in the potential environmental impacts if the minced bream was produced in the alternative systems. In comparison to other protein sources, the minced bream shows great potential, both now and in the future when the carbon budget may be limited to 0.5 kg CO2-eq per meal if we are to limit global warming to 1.5°Cabove pre-industrial levels.  Further studies are encouraged to collect more data and provide a better understanding of the environmental impacts of fish products. However, the results could function as an important benchmark that also highlights the potential of currently underutilized species of fish. / Behovet av mer hållbara proteinkällor ökar globalt till följd av matproduktionens stora klimatavtryck samt uppskattningar om en snabbt växande befolkning. Även om vegetariska proteinkällor har visats vara hållbara alternativ, finns en möjlighet att även andra resurser som i dagsläget inte utnyttjas har potential att bidra som hållbara proteinkällor. Livscykelanalys (LCA) är ett internationellt standardiserat verktyg som används för att utvärdera den potentiella miljöpåverkan från en produkt eller tjänst under hela livscykeln. En nyligen genomförd LCA visar att svenska karpfiskar har ett genomsnittligt potentiellt klimatavtryck på 0.77 kg CO2- ekvivalenter per kg ätlig produkt, vilket är avsevärt mycket lägre den potentiella klimatpåverkan hos många av de proteinkällor som idag konsumeras i större utsträckning. Braxen är en karpfisk som tidigare konsumerats i Sverige men som numera fångas enbart som en bifångst som släpps tillbaka.  Denna studie syftar till att utvärdera den potentiella miljöpåverkan av braxenfärs som produceras i Stockholm på braxen fångad som bifångst till gösfiske i Mälaren. Studien undersöker också hur den potentiella miljöpåverkan kan förändras i alternativa system och hur den potentiella klimatpåverkan kan jämföras med den potentiella klimatpåverkan från andra proteinkällor som konsumeras i Sverige. Resultaten från studien bekräftar många av slutsatserna i litteraturen som granskats, som att fisket och transporter identifierats som hotspots. Resultatet visar också en låg potentiell miljöpåverkan från braxenfärsen i det nuvarande systemet men en betydande ökning av den potentiella miljöpåverkan om braxenfärsen produceras i de alternativa systemen. Jämfört med andra proteinkällor visar braxenfärsen stor potential både nu och i framtiden när koldioxidbudgeten kan begränsas till 0.5 kg CO2-ekvivalenter per huvudmåltid om den globala uppvärmningen ska begränsas till 1.5 °Cöver förindustriella nivåer.  Ytterligare studier uppmuntras för att samla in mer data och ge en bättre förståelse för fiskprodukters miljöpåverkan. Resultatet kan dock fungera som ett viktigt riktmärke som också belyser potentialen hos för närvarande underutnyttjade fiskarter.
8

Hans Werner Henze - Drei Tentos : ur "Kammermusik 1958"

Benson, Andreas January 2016 (has links)
I denna studie går jag igenom min analys och förklarar relevanta delar av min konstnärliga samt tekniska tolkning av Hans Werner Henzes Drei Tentos. I inledningen ger jag en bild av min egen bakgrund och min ingång till detta verk. Huvudsyftet med studien är att analysera verket och att kunna komma fram till direkta och konkreta direktiv till den konstnärliga interpretationen. För att göra detta använder jag mig av partitur- och notationsprogrammet Sibelius (7.5) samt ordbehandlingsprogrammet Word (2011). Studien ger svar på en del frågor men lämnar också öppna trådar som kan besvaras genom mer ingående studier av kompositörens egen bakgrund och om hela verket ”Kammermusik 1958”.
9

Purification and characterization of two isoforms of aldehyde dehydrogenase from the liver of black seabream Mylio macrocephalus.

January 2002 (has links)
by Tang Wai Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 91-110). / Abstracts in English and Chinese. / Acknowledgements / 論文摘要 / Abstract / Abbreviations / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Aldehyde Dehydrogenase Extended Family --- p.1 / Chapter 1.1.1 --- Phylogenetic Tree --- p.2 / Chapter 1.1.2 --- Physiological Functions --- p.4 / Chapter 1.1.3 --- Structural Conservations --- p.7 / Chapter 1.2 --- ALDH-1 and ALDH-2 --- p.9 / Chapter 1.3 --- Antiquitin --- p.11 / Chapter 1.4 --- Osmoregulation --- p.14 / Chapter 1.4.1 --- Osmoprotectant --- p.14 / Chapter 1.4.2 --- Betaine Aldehyde Dehydrogenase --- p.15 / Chapter 1.5 --- Objectives of the Present Study --- p.18 / Chapter Chapter 2 --- Purification and Characterization of Seabream ALDH-2 and Antiquitin --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials --- p.21 / Chapter 2.3 --- Methodology / Chapter 2.3.1 --- Preparation of Crude Tissue Extract --- p.22 / Chapter 2.3.2 --- Synthesis of α-Cyanocinnamate Sepharose --- p.22 / Chapter 2.3.3 --- Synthesis of p-Hydroxyacetophenone Sepharose --- p.23 / Chapter 2.3.4 --- Purification of ALDH-2 --- p.23 / Chapter 2.3.5 --- Purification of Antiquitin --- p.24 / Chapter 2.3.6 --- Enzyme and Protein Assays --- p.24 / Chapter 2.3.7 --- Electrophoretic Procedures / Chapter 2.3.7.1 --- Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) --- p.26 / Chapter 2.3.7.2 --- Native PAGE --- p.27 / Chapter 2.3.7.3 --- Isoelectric focusing (IEF) --- p.27 / Chapter 2.3.8 --- N-terminal Amino Acid Sequencing --- p.28 / Chapter 2.4 --- Results / Chapter 2.4.1 --- Tissue Distribution of ALDH --- p.29 / Chapter 2.4.2 --- Purification and Molecular Properties of ALDH-2 --- p.31 / Chapter 2.4.3 --- Kinetic Properties of ALDH-2 --- p.42 / Chapter 2.4.4 --- Purification and Molecular Properties of Antiquitin --- p.49 / Chapter 2.4.5 --- Kinetic Properties of Antiquitin --- p.54 / Chapter Chapter 3 --- Discussion / Chapter 3.1 --- Tissue Distribution --- p.66 / Chapter 3.2 --- N-terminal Amino Acid Sequencing --- p.67 / Chapter 3.3 --- Purification of Seabream ALDH --- p.68 / Chapter 3.3.1 --- Separation of Two ALDH isoforms --- p.69 / Chapter 3.3.2 --- Binding Affinity of α-Cyanocinnamate Sepharose --- p.70 / Chapter 3.3.3 --- Purification --- p.72 / Chapter 3.4 --- Electrophoretic Properties --- p.73 / Chapter 3.5 --- pH and Temperature Stability --- p.74 / Chapter 3.6 --- Substrate Specificity --- p.77 / Chapter 3.7 --- Possible Functions of Antiquitin --- p.80 / Chapter 3.8 --- Future Prospects --- p.84 / Chapter Chapter 4 --- Conclusion --- p.90 / Chapter Chapter 5 --- References --- p.91
10

Cloning, expression and crystallization of black seabream (acanthopagrus schlegeli) antiquitin. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Antiquitin (ATQ) belongs to the superfamily of aldehyde dehydrogenase (ALDH). It is an evolutionarily conserved protein as shown from its high amino acid sequence identity between human and its plant counterparts. Therefore, ATQ is believed to play an important physiological role. Until now, however, studies on ATQ are limited and its cellular function is uncertain. Recently, we have first demonstrated the aldehyde oxidizing ability of ATQ purified from the liver of black seabream (Acanthopagrus schlegeli). To further investigate this protein, different attempts have been made. / Recombinant ATQ has been successfully expressed in E. coli. Kinetics studies showed that it possessed similar characteristics with its native enzyme. The recombinant protein was produced in large amount for protein crystallization. Crystal of ATQ was obtained and its X-ray structure was solved to 2.8 A in complex with NAD+. Tetrameric ATQ was a dimer of dimer. Three domains can be found in the subunit structure of ATQ, the NAD+-binding domain, catalytic domain and oligomerization domain. In each of the NAD+-binding domain, one molecule of NAD + could be found. The overall structure of ATQ was similar to other tetrameric ALDHs, but the coenzyme binding was in a single "hydride transfer" conformation and the density was well-defined which was contrast to most ALDH structures. Structural study of the substrate-binding pocket explained the failure of ATQ in oxidizing several aldehydes which is specific to certain members of ALDH. / The ATQ full-length cDNA of black seabream was obtained. It consisted of 2309 by with a 153 nucleotide long 5' UTR, and a 209 nucleotide long 3' UTR. An ORF of 1533 by which encoded a protein with 511 amino acids was found. This putative protein showed the highest of 87% sequence identity with zebrafish ATQ, and &sim;60% with plant ATQs. Tissue distribution was studied by RT-PCR. A high level of mRNA expression was observed in liver and kidney. Subcellular localization study using green fluorescent protein (GFP) fusion protein showed that ATQ was expressed in cytoplasm. However, another in-frame initiation methionine (M1) was found 31 residues before this generally accepted methionine (M2). Both iPSORT analysis and experimental studies using GFP fusion protein indicated that the 31 amino acid peptide contained a mitochondrial-targeting signal. / Tang Wai Kwan. / "July 2005." / Adviser: Fong Wing Ping. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3603. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 130-145). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Page generated in 0.4178 seconds